Improvements:
- Minor improvements to fluid pipe extraction, fillers and pipe icon handling (asie)
Bugfixes:
- [#2564] BC pipes lose liquid when different fluids mix in them. (asie - thanks MatthiasM2 for the 6.4.x workaround)
- Combustion engine not updating the fuel RF/t value (asie)
- Error while loading robot resources (hea3ven)
- Invalid engine rendering size (asie - introduced in 6.4.6)